PDFsharp & MigraDoc Foundation

I have been using pdfSharp for some time and I find it extremely useful.

However, I don't know what is the best approach to retrieve the width (in user coordinates) of a text string that needs to be included in the document; similarly, how to get the width of each character that needs to be displayed.

I am currently using Ghostscript to display pdf documents, and I would like to be able to calculate the width (in user coordinates) of a specific text string that is displayed on the screen. Using pdfsharp I think that I can extract the position at which the text rendering starts; but i don't know how to calculate the width of the each character in that string. Thanks in advance for any suggestion.